Creating A Swap Logical Volume; Extending A Swap Device; Reducing The Size Of A Swap Device; Administering Dump Logical Volumes - HP -UX 11i Administrator's Manual

If you plan device swap areas in addition to primary swap, you get the best performance when
the device swap areas are on different physical volumes. This configuration allows for the
interleaving of I/O to the physical volumes when swapping occurs.
To create interleaved swap, create multiple logical volumes for swap, with each logical volume
on a separate disk. You must use HP-UX commands to help you obtain this configuration. HP SMH
does not allow you to create a logical volume on a specific disk. See
to a Specific Disk" (page
You can configure your swap space as described in HP-UX System Administrator's Guide: Overview.
NOTE: You must reboot the system for the system to recognize changes to the swap configuration.

Creating a Swap Logical Volume

To create a swap logical volume, use the lvcreate command. You must set a contiguous allocation
policy using the -C y option. For example:
# lvcreate -C y -n swap_lvol /dev/vgnn
For more information, see lvcreate(1M).
If you create a logical volume to use as primary swap, use the lvlnboot command with the -s
option to update the swap information used by LVM at boot. For example:
# lvlnboot -s /dev/vgnn/swap_lvol

Extending a Swap Device

If you are using a logical volume for swap, you must increase the logical volume size before
increasing the swap size. You can extend the logical volume using lvextend or HP SMH.
Swap logical volumes must be contiguous, so extending the logical volume succeeds only if there
are physical extents available at the end of the existing logical volume. If contiguous disk space
is not available, create a new contiguous logical volume for primary swap within the root volume
group. You do not need to designate a specific disk. For example:
# lvcreate -C y -L 48 -n pswap /dev/vgroot
After creating a logical volume to use as primary swap, use lvlnboot to update the boot
information:
# lvlnboot -s /dev/vgroot/pswap

Reducing the Size of a Swap Device

If you are using a logical volume for swap, you must reduce the swap size before reducing the
size of the logical volume. You can reduce the size of the logical volume using lvreduce or HP
SMH.

Administering Dump Logical Volumes

NOTE: Version 2.0 and 2.1 volume groups do not support dump logical volumes.
This section describes LVM information about using logical volumes as dump devices. For information
on configuring and managing dump devices, see HP-UX System Administrator's Guide: Overview.

Creating a Dump Logical Volume

To create a dump logical volume, use the lvcreate command. You must set a contiguous allocation
policy using the -C y option, and disable bad block relocation using the -r n option. (Note: the
-r option is only required for Version 1.0 volume groups. It is not supported on Version 2.x and
will be ignored.) For example:
# lvcreate -C y -r n -n dump_lvol /dev/vgnn
For more information, see lvcreate(1M).
102 Administering LVM
54).
"Extending a Logical Volume